I just did this install from with the kit from nsn motorsports. They were really helpful, shipped it out right away, and the had decent prices. The install is a little involved and does take a lot of time. Here is the install on the forms http://www.mazda3forums.com/index.php?topic=45357
. The passenger side will probably take you well over an hour but the drivers side will only take 30 mins or so.
On the right side where it says "Go under the car with your 10mm ratcheting wrench and spend about 30-40min taking out that stupid bolt.
Took me 1hr, taking pics and trying to find a faster way to get it out.
The ONLY way to get that out without lowering the cross member is to use the ratcheting wrench,
then your fingers (from both hands, I have small fingers and I can’t get in there with just one) to finish getting it out."
Go out and buy sears ratcheting wrenches with the flexable heads. After i got those the project went so much faster. They are like $110 for 7 wrenches but i made sure to take care of them and return them after i was finished.
It is definitely worth the time though because my rear camber is right within the correct range.